Q. I have a peach tree that has produced magnificent fruit for over 15 years- for the past two seasons I have seen no production or at best tiny fruit that doesn't mature- I have studied your blog and believe that my tree has peach tree borer damage. I live in southern California- zone 9. Should I try to save the tree or is it a lost cause and if so what applications can I use to restore it? I prefer organic methods.
A. I am more familiar with the problems in the Mojave Desert but I would probably agree with you that it is some type of borer.
Peach trees can be fairly short-lived in many locale because of borers. This includes other countries I have visited. The borers are different but the result is the same. At our orchard in North Las Vegas peach trees that are 15 years old are getting up there in age and a 20 year old tree is old.
All that being said you can always find someone who has a peach tree that is 40 years old but it is rare and they were lucky or possibly the variety but trees that old are usually not productive any more.
I would remove it and replace it with another this fall if you can find a variety you like. If you are in a very temperate part of southern California like the San Diego area or along the coast you could do it any time. In the hot desert area, wait until it cools off.